South Florida's Anna Kournikova reached No. 8 as a women's tennis player and now is a coach on NBC's "The Biggest Loser." She also has been called one of the world's sexiest athletes.

Injuries cut short her professional tennis career in 2003 but she remains active. These days, she exercises several days a week to remain healthy, burn stress, gain energy and work on her curves.

A longtime trainer with The Boys & Girls Clubs, Kournikova says "The Biggest Loser" enables her to share her knowledge and experience with a wider audience. She considers it a "dream job."

Q: Why do you keep fit?

A: I crave exercise, crave sweating, crave stretching. Like a little baby stretches and yawns after waking up, it feels good. All your joints are lubricated.

For me, exercise is definitely about health. But it's also a great stress-reliever. I get on the treadmill and read a magazine, or listen to music, and feel like I'm releasing that energy, that stress.

Exercise gives me great energy. It's about being healthy, having energy, [parents] spending quality time with children. Looking good is literally a bonus. It's not about a certain size. Everybody is different. As long as you're healthy, that's most important.

I'm a typical slender Russian. I'm not a big girl, not a strong girl, so for me to have curves or maintain muscle mass I have to do weight training. Cardio just burns the calories.

Q: What's your workout schedule?

A: I try to do two, three days in a row, then a day off, then two or three again. I believe in the days off because the body will work better after a break. Sometimes, I have to force myself to take a day off.

In hotels, I squeeze in a workout. And I walk in the airport instead of taking the mover.

Q: What exercises do you do?

A: I mix it up. I play tennis three or four times a week, go to the gym, do StairMaster, swimming, planks, yoga, which didn't go so well last year because I injured my knee.

Yesterday I did treadmill and weight training. Today I did elliptical and weight training. I change up the weight training. Low reps (repetitions) and high weight yesterday, today high reps and low weight. I mainly do lower body and core. Core is crucial because I have a back problem. At least three times a week, I do core.

I do lower body mainly, but upper body a little. My arms tend to bulk up pretty fast. I focus on the girl parts, like the butt and legs.

If I don't want to think at the gym, I'll go through every machine. I'll space out. When I have energy and want to be creative, I'll create a routine.

Q: Where do you work out?

A: I bounce around to three gyms in South Beach, depending on where my appointments are and where I am in the city today. All the gyms have different machines.

A lot of times, I work out at my home. I have a treadmill. I have a stability ball, dumbbells for lunges. I run up the stairs. I do a lot of mat stuff.

Q: Do you work out with a trainer or partner?

A: I work out by myself. No trainer. I like zoning out.

Q: Ever take extended breaks from working out?

A: The longest I didn't work out was when I went to Iraq and Afghanistan with the USO [in 2009]. Otherwise, the longest I haven't gone to a gym is 10 days. But even then, I still had to jog outside.

Obviously, when I have an injury I modify. Last year, I hurt my knee doing yoga, so then I could do only bike.

Q: Why did you get involved with "The Biggest Loser"?

A: I've been a professional athlete all my life, coached and trained by the best coaches, nutritionists — and I really wanted to share all that knowledge and experience.

When I stopped playing full-time tennis at 21, I was playing with kids still at charity events and clubs. That's what I do. I can't imagine my life being without sports.

I've worked with The Boys & Girls Clubs for a long time, getting kids into physical activities. So "Biggest Loser" has been a natural transition for me. I'm passionate about the healthy, active lifestyle. It's been a dream job.

Q: How did you get the job?

A: I had a guest spot on it a couple of years ago. When I found out Jillian [Michaels] was leaving, I pursued it. I had meetings with producers, auditioned, did some screen shots, then I got the job. It was awesome.

Q: Does your family keep fit?

A: My parents are very fit. Both were athletes. Dad was a Greco-Roman wrestler in Moscow. My mom was a runner, 400 meters, a track star. It's in my blood.

My little brother now is playing junior golf, won a bunch of tournaments this summer. My mom plays tennis every day in a league. My dad works out. It is a lifestyle.

Q: Do you have a personal fitness motto or philosophy?

A: You don't want to leave things for tomorrow, because that's what you're going to do tomorrow. Even if only 15 minutes, start today, start now.

Q: Do you have any physical problems that hinder exercise?

A: I'm lucky during this period. The trick is to do a lot of preventive care. If you're starting to get sore or achy, use ice or Tylenol. Prevent minor problems.

But I do get all kinds of physical problems: hurt knee last year and chronic tendinitis in my wrist from playing tennis. Sometimes that flares up. And my back, and the screw in my foot from a stress fracture.

Q: Any health vices?

A: Coffee?

Q: What's your typical daily diet?

A: I believe in eating five small meals. It's hard to sustain, but the key is planning and preparing. Most of the time we make bad food decisions when stressed or in a rush.

I love eating two, three days really clean — veggies, chicken, fish, lean meat — then splurge with pizza or cheeseburgers or ice cream. I don't mind having a Snickers bar every other day. I don't want that as a forbidden fruit. The key is finding what works with you and being in moderation. I love pizza, but in moderation.

It's about having the right kind of nutrition: fruits, vegetables, avocados, olive oil.

First thing when I wake up is freshly squeezed grapefruit with lemon inside. Twenty minutes later, granola cereal, yogurt with berries, maybe eggs.

Five meals are really difficult. I walk around with … snacks in my purse: carrots, almonds. Ten almonds have 100 calories and are a great, healthy snack. Sometimes I eat a power bar or berries. Or banana.

Q: What do you drink typically?

A: I know you're supposed to drink eight, eight-ounce glasses of water each day. Sometimes I get it, sometimes I don't.

I drink soda, water, Champagne, whatever. I don't drink a lot, a glass of Champagne or a cocktail occasionally. I do realize soda is not that great for you supposedly, but I'll have a Diet Coke.

Q: Do you take any vitamins or sports supplements?

A: I don't like to swallow pills so I add multi-vitamin powder, Emergen-C, into my water. Doctors say if you have proper nutrition and diet, you should be getting everything you need [without supplements].

Q: Any advice for South Florida residents looking to get fit?

A: Start taking care of your health, so you can be around for your kids. It's not about shape or size. It's about feeling good, having energy, adding years to your life.

Most important is to treat your body with respect. We have one body. Yeah, it's great to look good, but I want my bones, joints, organs to be OK.